fix(l1): don't cancel storage healer if state healing ends earlier

[fmoletta]

Motivation
Currenlty, when state healing finishes, the storage healer is cancelled, even if there are still storages to be fetched and the tries are not stale yet, which slows down storage healing due to the frequent restarts if state healing ends before storage healing. This PR aims to fix this by changing the behaviour to not cancel storage healing if state healing is complete, but to instead give this information to the storage healer via an AtomicBoo, so that it can decide whether to stop based on if the state has become stale, or if no more paths are left to heal and mo more will be added by the state healer.

Description

• Add AtomicBool param to storage_healer to signal whether state healing has ended
• Don't cancel storage healing if state healer ended due to state healing being complete
• End storage healer if there are no more pending storages left & state healing has ended
• (Misc) Remove outdated comment

Closes #issue_number

[github-actions]

Lines of code report

Total lines added: 16
Total lines removed: 0
Total lines changed: 16

Detailed view

+------------------------------------------------------+-------+------+
| File                                                 | Lines | Diff |
+------------------------------------------------------+-------+------+
| ethrex/crates/networking/p2p/sync.rs                 | 573   | +6   |
+------------------------------------------------------+-------+------+
| ethrex/crates/networking/p2p/sync/storage_healing.rs | 97    | +10  |
+------------------------------------------------------+-------+------+